On the calm water of the pond is a boat length of 4 m, located perpendicular to the coast. At the stern of the boat is a man. Weight boat 210 kg human weight of 60 kg. The man moved from the stern to the bow of the boat. How far have moved at the same time with respect to the shore and the boat people?

Detailed solution shorthand terms, formulas and laws used in the decision, the withdrawal of the calculation formula and the response.
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